The present invention relates to an apparatus for connecting battery plate units through apertures in battery cell partitions, and more particularly to an apparatus constructed for effecting each connection by fusing together lead projections within the apertures.
Lead storage batteries are well known and consist of a series of cells, usually three or six, connected in series to provide the desired output of voltage. Each cell consists of a plurality of positive and negative plates carried in electrolyte, with the positive plates being connected together by a battery strap at one side of the top of the plates and the negative plates being similarly connected together at the other side by another battery strap so as to provide parallel connections between the plates in each cell. In order to provide the desired series connection between cells, the plate units are lined up so that alternative positive and negative battery straps will appear on each side at the top of the plate units. Lugs or projections are provided on the straps and connection is effected by electrically joining these lugs or projections.
In early battery units each battery strap had a post projecting from the top of the battery casing and the connection between cells was made by an externally located strap. Later developments provided for placing such a strap internally just under the top of the battery casing. This provided for a saving in lead and a completely internal structure having obvious advantages. However, direct connection through the battery partitions provides even more advantages, such as short current path, lower resistance, less lead, etc. Considerable effort has been expended in providing the connections to the positive and negative battery straps directly through a partition in an efficient and reliable manner. However, it is considered necessary to utilize lead elements within the cells in order to resist corrosive conditions therein and it is particularly difficult to process lead in production machinery. In addition, it is important to provide a positive seal between cell units so that electrolyte cannot pass from one cell to another, and this seal should not require separate sealing materials such as epoxy resins.
It has been proposed to provide an aperture in each cell partition just above the battery straps to be connected and to provide a connector therethrough which in turn will be connected to each battery strap. For example, such connections have been made as indicated in U.S. Pat. No. 3,313,658 issued to Sabatino et al, Apr. 11, 1967. Other methods, such as that shown in our co-pending application referenced above, are preferred, but in any case it is desirable to provide an apparatus which is capable of accomplishing good fusion of the lead in the aperture and making a good completely sealed connection. Typically, such an apparatus consists of electrodes which are placed over the lugs and provided with a sufficient electric energy source to provide the burning or welding necessary. However, the cell spaces are rather small, and in a six cell battery five connectors must be welded. Accordingly, processing has been somewhat tedious and expensive and a need has arisen for a reliable machine capable of providing the connection in an automatic and reliable manner.